This invention relates generally to motion dampers or snubbers for lifts, jacks or like lifting devices.
Jacks or lifting devices known as one end lifts have met with wide commercial acceptance in auto repair garages, truck maintenance facilities, and similar shops. These lifts are favored because the lift user can relatively easily elevate an entire end of a vehicle or like load, providing extensive access to the vehicle underside. The lifts can be moved about from one job to another, and are not as expensive as less versatile hoists or other devices which are sometimes installed in a shop floor for raising an entire vehicle.
In use, hydraulic or pneumatic pressure raises a lift saddle which engages one end of a vehicle and elevates the vehicle end to a work height. However, if the vehicle or other lifted load should shift or fall off a pneumatic lift, that pressure exerted by the compressed air which was used to lift both the saddle and the load may be applied against only the lifting saddle alone, resulting in a very rapid saddle rising action. Rapid saddle rise is undesirable from a safety standpoint, for it can result in damage to the load, bystandstanders, or the lift itself.
While mechanisms have been offered to prevent or inhibit this sudden saddle rise, it is also necessary that, under normal lift use conditions, relatively prompt, positive saddle up and down motion be available to raise and lower the load in a normally expeditious manner.
It is therefore the general object of the present invention to provide apparatus for an improved one end lift which keeps the lift saddle and associated lifting parts from suddenly rising should the load be lost, yet which permits positive lift saddle up and down motion under normal, controlled conditions.
It is another object of the invention to provide a damping action to sudden lift part extension or saddle rise, but to interject only a minimum damping action under normal lift lowering conditions.
It is another object to provide a lift snubber mechanism which accomplishes these tasks, yet which is relatively easy to service when necessary. A related object is to provide such a snubber which can be removed and replaced or adjusted for proper action with a minimum of service effort and expense.
Another object is to provide a lift snubber which is relatively straightforward in design and inexpensive to manufacture, yet which is reliable and rugged in use.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.